1. Field of the Invention
This invention relates generally to form molded structures, and more particularly, to the manufacturer, installation and use of molded building component structures.
2. Description of the Related Art
In current construction practice, there are two known and common methods of building outdoor decks and balconies, to be used as part of building structure. The first is the classic redwood deck, which allows rain water to leak down between gaps in the planks. The second is the moisture resistant tile or liquid plastic coating deck.
Most people are familiar with redwood decks. Floor joists are attached to the house either cantilevered from the second floor, or built on beams and posts for a larger deck. The 2×6 (inch) dimensional redwood boards are nailed down flat perpendicular to the joists with a ¼ inch gap between the planks. This has been a very popular and attractive decking system.
One downside to this system is that redwood cracks and ages, and redwood is becoming more scarce and expensive. Recently, firms like Trex™ have addressed these problems by extruding synthetic decking planks, that are similar in shape and size to the redwood 2×6 planks. They can be sawed and drilled almost as easily as wood. By mixing plastic and sawdust these products are longer lasting than redwood, wear and look better than redwood over the years and claim to be termite and mold resistant.
The problem that both redwood and synthetic wood decks have is that they are not rain-proof. When it rains, the water drops down between the gaps of the boards, hitting the ground below and wetting the joists and beams. Over time this rots the structural wood, eventually requiring rebuilding of the deck, or worse, complete structural collapse, killing in many cases those on the deck at the time.
The other drawback is that no habitable space can be built below. A watertight decking system is required for this application. There has been a long history of watertight decks and balconies built over the years. The most common way is to build a slightly sloping hot mopped deck using modified bitumen and galvanized metal flashings, much the same way a flat roof is done by roofing contractors. The difference is that a walking deck must be built much stronger than a roof, and must have a hard, slip resistant surface over the asphalt coating. Typically this is done like a tile shower pan. Over the hot mop, ¾′ of grout is placed, properly sloped for drainage, then tile or stone or pavers are set, then grouted, and finally weather sealed. Finally flashing must be installed and checked to avoid leaks into the house during rain storms.
The hot mopped and tiled exterior rain resistant deck is a very expensive and complex endeavor, involving 4 or 5 building trades, spending weeks on each deck. And worse, the deck is the most vulnerable part of the house to the freeze thaw cycle, the expansion and contraction between hot and cold weather. During hot weather the deck may expand cracking the asphalt coating underneath which may have become brittle over time. In the cold weather the tiles may pull away from the house, allowing water infiltration. Then when it rains, water may seep below the tile and migrate to some other location where the asphalt is cracked, causing leaks down into the sheet rock ceiling below.
When the homeowner calls out the contractor it generally happens that the real point of leakage is hidden from view from the deck above. Many times the only fix is to tear up the expensive tile and hot mop and do it all again.
In part to address this problem of the invisible leak, as well as the high cost of the installation of rain-proof decks, many liquid epoxy and plastic walkable coatings have been developed over the past 20 years. Firms like Dex-O-Tex sell liquid coatings installed by factory-approved installers, in several coats and with special flashings and fiberglass reinforcing. A sand finish is tossed onto the final coat for skid resistance, and different colors are offered. Durability depends on the sloping and structural strength of the exterior grade plywood on which the liquid coats are spread. A 5-coat job may take a week to complete and is still a relatively expensive and risky endeavor. These have also been leaks and liability problems in housing projects. The deck must be inspected regularly and repaired promptly to protect the habitable areas below.
Therefore, what is need is a durable and reliable structure that can be used as a deck or building component, without introducing the aforementioned problems.